JPH0371873A - Printing apparatus - Google Patents

Abstract

PURPOSE:To obtain a printing apparatus low in noise and improved in assembling properties by using a porous structure having a porous layer whose specific gravity is continuously changed in the thickness or surface direction thereof and the air impermeable fusion layer fused to and integrated with one surface of the porous layer and covering a mechanical main part with said structure so that the porous layer is set to the inside and the fusion layer is set to the outside. CONSTITUTION:A top surface panel 60 having a U-shaped cross-section is formed using a porous structure (multilayer material). A fusion layer 15 has high specific gravity and may be air-pemeable or air-impermeable. A porous layer 16 has low specific gravity and is normally ail-permeable and the void ratio thereof is continuously changed in the thickness direction thereof. A skin layer 17 normally has specific gravity intermediate between the specific gravity of the fusion layer 15 and that of the porous layer 16. When the multilayer material 14 is used as a sound absorbing material by integrating the fusion layer 15, the porous layer 16 and the skin layer 17, the porous layer 16 is opposed to a sound source to absorb and attenuate sound energy and the transmission of a sonic wave is prevented by the fusion layer 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer device incorporating a noise generating source such as a cooling fan motor.

[Prior Art] Fig. 19 is an exploded perspective view showing a printer device as a conventional device with a built-in noise source. , (52) is a chassis that fixes the mechanical body (53) of the printer device, (54) is a rear plate that covers the rear surface of the printer device, and (55) is the mechanical body (53) of the printer device.
Fan motor for cooling the heat dissipation section attached to (56)
is a design panel that covers the front of the printer device.

The mechanical part main body (53) is screwed and fixed to the chassis (52) with screws not shown, and the fan motor (55) is screwed to a part of the sheet metal structure of the mechanical part main body (53) with screws not shown. Fixed. And this fan motor (5
5) operates at the same time as the printing operation of the main body of the mechanical part, and sends an air flow to the heat radiating part of the head, which generates heat, to cool it down.

In addition, as a structure that covers the machine main body (53) and other printer device parts, a rear plate (54) and a top plate (
51) are each screwed to the chassis (52), and a design panel (56) is fitted from the front side to form the entire printer device.

FIG. 20 is a schematic diagram showing the installation structure of the top plate (51). As shown in FIG. As shown in B), insert screws (58) through holes (57) provided on both vertical sides (51a) of the top plate (51) through screw holes (59) provided on both vertical sides (52a) of the chassis (52). Screw into the top plate (51) to fix the top plate (52) to the bottom plate (52).

[Problems to be Solved by the Invention] Since the conventional printer device is configured as described above, the entire device is constructed with a top panel (51), a rear panel (54), a design panel (56), etc., which have a weak soundproofing effect. The vibration noise generated by the fan motor (55) and the mechanical operation noise generated by the mechanical body (53) have a high rate of leaking to the outside of the device, causing noise pollution in the area where the device is installed. There was a problem with letting it work.

The present invention has been made to solve the above-mentioned problems, and aims to provide a printer device with low noise and easy assembly.

[Means for Solving the Problems] A printer device according to the present invention includes a porous layer whose specific gravity is continuously changed in the thickness direction or the surface direction of the layer, and a porous layer fused to one side of the porous layer. using a porous structure having a non-breathable fusion layer integrated with the porous layer,
The main body of the mechanical part that generates noise is covered with the fusion layer on the outside.

[Function] The printer device of the present invention covers the main body of the mechanical part with a porous structure having a porous layer whose specific gravity changes in the thickness direction or the surface direction of the layer, thereby reducing noise to the outside of the device. Less leakage.

In addition, the porous structure can be assembled to the chassis without the need for screws due to the integrally molded engaging claws, improving ease of assembly.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In FIG. 1, in which the same parts as those in FIG.
This is a top plate with a U-shaped cross section.

Next, the structure, manufacturing method, and characteristics of a porous structure (hereinafter, a porous structure or a layered structure is also referred to as a multilayer material) made of a sound-absorbing material and a non-breathable fused layer member used in the present invention will be explained. The details are described in Japanese Patent Application No. 110996/1999 filed on April 28, 1999, entitled "Porous Structure".

FIGS. 3(A) and 3(B) are diagrams each schematically showing a cross section cut in the thickness direction of the multilayer material (14). In the figure, (15) is a layer with a high specific gravity, such as a fusion layer, which may be either air permeable or non-air permeable.

(16) is a porous layer with low specific gravity and is usually breathable, and the porosity changes continuously in the thickness direction.

(17) has a normal specific gravity of the fused layer (15) and the porous layer (16).
), for example, a fused layer with a thickness of less than 100 microns.

The multilayer material (14) includes a fusion layer (15) and a porous layer (16).
Similarly, the fusion layer (15), porous layer (16), and skin layer (17) are integrated.

When the multilayer material (14) is used as a sound absorbing material, the porous layer (16) is placed facing the noise source to absorb and attenuate sound energy, and the fusion layer (15) prevents the transmission of sound waves. prevent.

Next, we will discuss the manufacturing method and characteristics of the porous layer whose specific gravity is continuously changed in the layer thickness direction or layer plane direction, which constitutes the multilayer material (porous structure) (14) as described above. explain.

First, the manufacturing method will be explained.

FIG. 4 is a cross-sectional view of a mold configuration for explaining a method for manufacturing a multilayer material. In the figure, (18) is a concave mold, which is made of a material with good thermal conductivity, such as aluminum.
(19) is a convex mold, which is also made of aluminum.

(20) and (21) are heaters that raise the temperature of the mold, and the concave mold (18) is heated to a higher temperature than the convex mold (19).

Manufacturing method ■ A case will be described in which a porous structure is molded using a granular thermoplastic resin material as a raw material.

The temperature of the wall (22) of the four-side mold (18) is the same as that of the concave mold (
18) and a closed space formed by the convex mold (19).
23) The temperature of the wall part (24) of the convex side mold (19) is set at a temperature higher than the softening temperature of the granular material, which is the raw material to be placed inside, and lower than the thermal decomposition temperature, usually 150 to 240°C. a temperature lower than the temperature of the wall (22) of the mold (18);
For example, around the temperature at which the granular material used as the raw material softens, usually 7
Set at 0-180°C.

Then, the granular material that has come into contact with the high-temperature wall (22) of the concave mold (18) will eventually become a layer with a high specific gravity, that is, a fused layer (15), and depending on the degree of fusion, it will change from breathable to non-permeable. Changes to breathability.

Since the wall (24) of the convex side mold (work 9) is lower in temperature than the high temperature wall (22), the granular material from the wall (24) to the fusion layer (15) does not reach complete fluidity. However, in a semi-fluid state, each particulate material is welded at the contact portion, and finally a porous layer (16) welded to the fused layer (15) is formed.

This porous layer (16) is normally breathable, but depending on the mixture of materials such as binder, it becomes non-breathable.

In this way, a layer with a high specific gravity and a porous layer with a low specific gravity can be integrally molded at the same time.

When the diameter of the granular material is 0.2 mm or less, the pore diameter becomes small and the function of the multilayer material, such as sound absorption properties, deteriorates.

Furthermore, when attempting to increase the pore diameter, the degree of fusion between particles decreases, resulting in a decrease in mechanical strength.

Furthermore, when the diameter becomes 3 or more, the sound absorption properties deteriorate.

Note that typical examples of the granular material raw material for the thermoplastic resin include PP (polypropylene), AS (acrylic styrene), and styrene.

In addition, when methyl ethyl ketone (MEK) cellulose, varnish, or acetone is sprayed or mixed as a binder into the thermoplastic resin granular material, the adhesion strength of each granular material of the multilayer material increases, and the mechanical strength improves. Improves handling.

Manufacturing method ■ The case of molding a multilayer material using a thermosetting resin granular material as a raw material will be explained.

In the same manner as manufacturing method ■, the wall (22) of the concave side mold (18)
The temperature of the wall (24) of the convex mold (19) is set to be higher than the softening temperature of the granular material and lower than the thermal decomposition temperature, and the temperature of the wall (22) of the concave mold (18) is set to It is set near the temperature at which the granular material softens, which is lower than the temperature.

Here, the molds (18) and (19) are filled with thermosetting resin such as phenol, PBT (polybutylene terephthalate), PET (polyethylene terephthalate).
Particles of a granular material with a diameter of about 0.2 to 3 mm are mixed with a binder such as cellulose, varnish, various adhesives, etc., and the molds (18) and (19) are closed under pressure. Heat for several minutes to several hours.

This heating is performed at the set temperature of the molds (18) and (19) mentioned above, and the pressing force is 1 kg/in the heated state. , 2 to several t. n/. . It is 2.

In this way, the high temperature wall part (22) of the concave mold (18)
) The granular material that comes into contact with the material softens and is bonded with a binder to form a layer with a high specific gravity, which changes from breathable to non-breathable depending on the degree of softening.

Since the wall (24) of the convex mold (19) is at a low temperature due to the high temperature wall (22), the granular material from the wall (24) to the layer (15) with high specific gravity is completely fluidized. However, in a semi-fluid state, each particulate material is bonded with a binder at the contact part, and finally the porous layer (1G) bonded to the layer (15) with a high specific gravity is oriented in one direction. It is formed.

This porous layer (16) is normally breathable, but when the amount of binder mixed becomes large, it becomes non-breathable.

Furthermore, in order to change the specific gravity of the porous layer of the multilayer material in the layer plane direction of the porous layer, the temperature of the mold on the low temperature side may be changed along the layer plane direction.

Then, among the molds on the low temperature side, the porous layer portion facing the higher temperature portion has a higher specific gravity, and the porous layer portion facing the lower temperature portion has a lower specific gravity.

On the other hand, in the above-mentioned manufacturing method, since the multilayer material can be integrally molded, the mold can be used, so that multilayer materials of various shapes, especially complex shapes, can be easily produced.

Next, various characteristics and applications of the porous layer manufactured in this way, in which the specific gravity is continuously changed in the thickness direction or in the plane direction of the layer, will be explained.

(i) Sound absorption characteristics Figure 5 shows an example of the porosity (specific gravity) distribution in the thickness direction of a 10-thick porous structure (mostly the entire area is porous layer) formed by manufacturing method ①. It is a diagram.

In FIG. 5, four lines A and C indicate a porosity of approximately 25 (%) and 10 (%), respectively, in the thickness direction. The porosity has a distribution in the thickness direction and continuously changes in the range of 10 to 20 (%).

When using this type of porous structure as a sound absorbing material, its sound absorbing properties become an issue.

Figure 6 shows the normal incidence sound absorption coefficients of the samples with the three types of porosity distributions shown in Figure 5 using JISA 1405r.
lPj formula for the normal incidence sound absorption coefficient of building materials using the in-pipe method
The results are shown below.

In addition, in the sample having a porosity distribution in the thickness direction of curve B, the side with a porosity of 10 (%) was set as the surface on which the sound waves were incident.

As can be seen from the figure, it was confirmed that the sample with the porosity distribution (curve B) had the best sound absorption coefficient characteristics.

The resin particles forming the porous layer described above may be cylindrical, columnar, cubic, etc. in addition to being spherical in shape. Thermoplastic resin particles with whiskers are suitable as raw materials because the whiskers are easily melted.

Furthermore, for the purpose of reducing the weight of the multilayer material, for example, foamed hollow granular materials or foamable materials can be used as raw materials.

Furthermore, short fibers may be mixed into the raw material for reinforcement, and thread-like thermoplastic resin may be mixed into the raw material as a binder.

In addition, it was confirmed that there is a range in the shape and major axis of the granular material that has better characteristics as a porous body, especially sound absorption characteristics. This will be explained below.

FIG. 7 is a diagram showing characteristic variations in the material incident sound absorption coefficient (variations in characteristics among five samples) when the shape of the granular moon is changed. Curve A has a granular moon with a diameter of 0.8
(ohm), cylindrical shape with length 1 (question), curve B
is a spherical object with a diameter of 1 (in).

In each case, the thickness of the porous layer was 10 (ms), and the frequency at which the sound absorption coefficient was measured was 2 (KHz). From the figure, it can be seen that the spherical one (curve B) has little difference in characteristics due to differences in samples and is extremely stable.

The reason for this is that in the case of a spherical shape, there is only one point of contact between the granular materials, so that the layer state of the granular materials becomes stable and uniform during molding.

In this way, it is better to use a spherical shape (sphere or ellipsoid), especially when stability of properties is required between samples.
A more preferable porous structure can be obtained.

It was also confirmed that the sound absorption properties differ depending on the major axis of the granular material. FIG. 8 shows the relationship between the long axis of the granular material and the sound absorption coefficient.

The thickness of the sample is 10 (IIll), and the measurement frequency is 2
(KHz). If the diameter of the granular material is too small,
If it is made too large, it becomes difficult for sound waves to penetrate into the porous body, or the specific acoustic impedance of the porous body becomes mismatched with the specific acoustic impedance of the air side, resulting in a decrease in sound absorption coefficient.

From FIG. 8, the major axis of the granular material is 0.
2-3.0 (old), preferably 1.0-2.0 (mm)
It was confirmed that sound absorption characteristics can be improved by setting the range of .

Next, other examples of porous structures used in the present invention will be described.

A porous structure consists of a porous layer with a specific gravity that changes continuously in the thickness direction or in the plane direction of the layer, and a solid layer with a smaller porosity and a higher specific gravity than the porous layer. This is what I did.

This solid layer becomes a fused layer when the granular material is a thermoplastic resin, and changes from breathable to non-breathable depending on the degree of fusion.

In addition, when the granular material is a thermosetting resin, the granular material softens and is bonded with a binder to form a layer with a high specific gravity.
Depending on the degree of softening, it varies from breathable to non-breathable.

Next, a typical method for manufacturing such a porous structure will be described.

Manufacturing example ■-■ In manufacturing method ■, the temperature of the wall (22) of the concave mold (18) is set to 150°C, and the temperature of the wall (22) of the convex mold (19) is set to 150°C.
Set the temperature of 4) to 100°C, and use ABS resin and 17, GTR-40 (grade) manufactured by Denki Kagaku Kogyo Co., Ltd.
Granular material of thermoplastic resin with a softening temperature of 86℃, diameter 1
Put the spherical particles No. 111 into the mold, mold (18), (19
) closed. At this time, the distance between the wall surfaces (22) and (24) was 10ffil11.

After 20 minutes in this state (that is, the heating state was maintained), the molds (18) and (19) were opened.

In addition, the pressurizing force in the heated state is 100 kg/cm
It was 2.

The multilayer material (14) thus formed is shown in FIG. This multilayer material (14) had a thickness of 10 mm, in which the thickness of the fused layer (15) was about 1 mm, and the thickness of the porous layer (16) was about 9 II11 mm.

Manufacturing method example ■-3 In manufacturing method ■, the temperature of the wall (22) of the concave mold (18) is set to 180°C, and the temperature of the wall (22) of the convex mold (19) is set to 180°C.
Set the temperature of 4) to 130℃, and as ABS resin,
GTR-40 (grade) manufactured by Denki Kagaku Kogyo Co., Ltd., thermoplastic resin granular material with a softening temperature of 86°C, diameter 1m
+++ spherical particles are put into a mold, molds (18) and (19
) closed. At this time, the distance between the wall surfaces (22) and (24) was 10 mm.

Leave the molds (18) and (19) in this state for 15 minutes.
was released. The pressing force in the heated state is 100 kg.
/cm2.

The multilayer material (14) formed at this time has a thickness of 10 mm+,
The thickness of the fusion layer (15) in it is about 1 layer, and the thickness of the porous layer (16
) had a thickness of approximately 9 mm, but compared to the molded multilayer material (14) of manufacturing method example -2, the surface portion of the porous layer (16) was partially fused, and a skin layer of approximately 30 μm was formed. It was done.

Manufacturing method example ■-2 In manufacturing method ■, the temperature of the wall (22) of the concave side mold (18) is set to 200°C, and the temperature of the wall (22) of the convex side mold (19) is set to 200°C.
) was set at 150°C, and as a thermosetting resin,
Phenol resin (manufactured by Meiwa Kasei Co., Ltd., MW-752 (
A granular material with a diameter of 1 mm was placed in a mold together with powdered cellulose (15% by weight ε) serving as a binder, and the molds (18) and (19) were closed.

The distance between the wall surfaces (22) and (24) was 10 mm.

After 25 minutes in this state (that is, the heating state was maintained), the molds (18) and (19) were opened.

The pressing force in the heated state is 150 kg/cm2.
Met. The multilayer material (14) formed in this way has a thickness of 1011III+, and the layer (15) with a high specific gravity is
The thickness is approximately 1 m11. The thickness of the porous layer (16) is approximately 9
It was mm.

Note that a granular material obtained by coating a thermosetting resin with a thermoplastic resin may be used as the raw material.

Next, the characteristics of the multilayer material (layered porous structure) formed as described above will be explained.

(i) Porosity Figure 10 is a curve diagram showing the porosity of the molded multilayer material. Curves ■-2 and ■-3 are manufactured by manufacturing method example ■-2 and manufacturing method example ■-3, respectively. The porosity (%) is shown relative to the thickness (am) of the multilayer material.

Both of the fused layers (15) are non-porous, and the porosity of the porous layer (16) of Example 2 changes continuously in the thickness direction, with the porosity being maximum at the surface (low temperature side). Become. The porosity of the porous layer (16) of Example II-3 changes continuously in the thickness direction, but the porosity reaches its maximum at the center of the porous layer (16) and decreases at the surface (low temperature side). Porosity decreases.

That is, the porosity of the surface area is between the maximum porosity of the porous layer (16) and the porosity of the fused layer (15), and a partially fused skin layer (17) is formed. It shows that

Note that, as long as the materials are the same, the smaller the porosity, the higher the specific gravity.

(Characteristics of the 10-layer porous structure When using a multilayer material as a sound absorbing material, its sound absorbing properties become an issue.

FIG. 11 is a curve diagram for comparing the normal incidence sound absorption coefficients, and shows the results of measuring the normal incidence sound absorption coefficients according to the above-mentioned JIS A 1405.

Curved material ■-2 is a multilayer material manufactured by manufacturing method ■-2 and has a thickness of 10
The curve "m+a" and the "secondary" curve respectively show the characteristics of a conventional sound absorbing material made of urethane foam with a thickness of 10 tam.

As can be seen from the figure, it was confirmed that the normal incidence sound absorption coefficient of the multilayer material is equal to or higher than that of the conventional sound absorbing material (urethane foam).

Figure 12 is a similar characteristic curve diagram of the normal incidence sound absorption coefficient. Both curves are the characteristics of the multilayer material manufactured by the above-mentioned method, and the actual -2 and actual -3 are the manufacturing method example ■-2 and the manufacturing method, respectively. Example ■-3
The characteristics of a multilayer material with a thickness of 10 mm manufactured in

The reason why the properties of Production Example (1)-3 are good is thought to be due to the optimization of the porosity of the surface area.

(ill) Effect of the skin layer Next, we will explain the phenomenon in which the sound absorption properties are improved by the skin layer and its optimum thickness.

First, ABS resin is used as the porous structure, and the thickness is 1
A sample of 01m11 was manufactured using the manufacturing method (2) described above.

Fig. 13 shows the actual measurement results of the porosity distribution of this sample, and Fig. 14 shows the normal incidence sound absorption coefficient characteristics of the sample with the smaller porosity without a sound wave incidence surface.

As is clear from the figure, in this sample, 400 (H
The sound absorption coefficient was maximum at a low frequency of z), and good sound absorption characteristics were obtained with the value exceeding 90(%).

At this time, as a result of fracture observation of the low porosity part on the sound wave incidence side of this sample using a microscope, it was found that the surface had become a nearly impermeable skin layer with a thickness of about 30 microns. Ta.

Furthermore, as a result of testing the sound absorption properties by varying the thickness of the skin layer, we found that when the thickness of the skin layer exceeds 100 microns, the skin layer acts not as a mass but as an elastic membrane (spring system). Therefore, the frequency of the highest sound absorption coefficient rose, and the desired effect could not be obtained.

Therefore, it was confirmed that the appropriate thickness of the skin layer is 100 microns or less.

The above-mentioned layered porous structure has mainly been explained in the case of two layers, but it can also be a three-layered porous structure or a porous structure with arbitrary layers and arbitrary materials.

FIG. 15 shows a cross-sectional view of a triple-layer porous structure (14a) consisting of a skin layer (17), a porous layer (16) and an impermeable solid layer (15).

When using this as a sound absorbing material, as described above, the skin layer (17) and the porous layer (16) have excellent sound absorbing properties, and the non-breathable solid layer (15) is a sound insulating material. Since it becomes a body, it is possible to create a structure that effectively exhibits both sound absorption and sound insulation functions.

It goes without saying that the present invention is not limited to the above example, and can be applied as a porous structure with any layer and any material depending on the application in each field.

Furthermore, by using a material containing particles other than resin particles as the granular material, the function of the porous structure can be expanded. An example of this will be described below.

First, the manufacturing method will be explained.

Manufacturing method example ■-1 Figure 16 shows 2 in the space (23) of the molds (18) and (19).
FIG. 3 is a sectional view showing the molds (18) and (19) filled with a material containing different kinds of grains and closed.

In the concave mold (18), iron particles (25) with a major axis of about 0.2+nm are first piled up and filled to a thickness of about 1 hole.
After that, fill ABS resin particles (26) with a major diameter of about 1 cm (same as those used in manufacturing method example -2) so that the height is about 2111 at higher than the height (10 mm) of the closed space (23). do.

After filling, the iron particles (25) and ABS resin particles (26) are filled by closely joining the convex mold (19) (plate-shaped mold in FIG. 16) to the four-side mold (18). compress the layers,
A packed layer of different types of grains is formed in the closed space (23).

Under the above conditions, the temperature is raised to a temperature higher than the softening temperature of the ABS resin particles, 86°C, that is, the concave mold temperature is 150°C and the convex mold temperature is 100°C, and heated for about 20 minutes. Iron grains (25
) has a melting point of about 1500°C, so the shape of the iron particles is maintained.

On the other hand, the ABS resin particles are particularly suitable for the wall (2) of the concave mold (18).
Since 2) is at a high temperature, the iron particles in contact with it also become high temperature, and the ABS resin particles (26) in contact with the iron particles (25)
is melted, and the melted ABS resin particles flow to surround the iron particles (25).

After heating, the multilayer body (14) is formed by cooling and forming a fused layer (14) with a thickness of 10 mm and mixed with chichitsu grains (25).
15) had a thickness of about 1 mm, and the porous layer (16) had a thickness of about 9 mm, forming an integrated laminate. The specific gravity of the fusion layer (15) is the same as the specific gravity of ABS resin when iron particles are not included, which is 1.05gr/cc, but when iron particles are added, only the fusion layer is cut and its specific gravity is As a result of determining 1lllJ, it was 4.4 gr/ec.

When the porous layer of a multilayer material is used as a sound absorbing material and the fused layer is used as a sound insulating material, the higher the specific gravity of the sound insulating material, the better the sound insulating properties, so this multilayer material has excellent sound insulating properties.

Previously, in order to increase the sound insulation of materials with light specific gravity such as ABS resin, it was necessary to increase the thickness of the material or attach metal such as iron plates, but with this manufacturing method, melting By mixing a material with a high specific gravity into the portion where the material is formed, a multilayer material having a porous layer and a fused layer with a higher specific gravity can be easily realized.

Next, a characteristic example (sound insulation characteristic) will be explained.

FIG. 18 is a curve diagram showing the sound insulation characteristics of this multilayer material.

Curve sample ■-2 and curve sample ■-1 are the multilayer material (without iron grains) manufactured by manufacturing method example ■-2 with a thickness of 10 mm, and the multilayer material manufactured by manufacturing method example ■-1 (with iron grains), respectively. ) thickness 101I
This shows the sound insulation properties of lil's.

This sound insulation property was measured using the property measuring device shown in FIG. Insert the multilayer material (14) to be measured into the vibrator (27) (100n+mφ), and place microphone No.
, 1, No. 2 (30), and (31) are installed.

Sound is input from the vibrator (27) through the speaker (28). The other end of the vibrator (27) is closed, and the closed end is filled with glass wool (29) having a length of about 1000 mm, and is treated to prevent sound from being reflected at the closed end. The sound pressure level of the incident wave emitted by the speaker (28) and incident on the multilayer material (14) is the same as the sound pressure level of the microphone No. 1 (
30), and the sound pressure level of the transmitted wave transmitted through the multilayer material is measured by microphone No. 2 (31).

The sound insulation degree (dB) of the multilayer material was evaluated by subtracting the sound pressure level of the transmitted wave from the sound pressure level of the incident wave.

As shown in Figure 18, the one containing iron particles (Real ■1)
The sound insulation degree is improved by about 10 dB compared to the one without iron particles (actual ■-2).

In the above-mentioned embodiment, the particles mixed with the resin particles were iron particles, but other metals, glass, and other materials with high specific gravity can also exhibit similar effects.

In addition, in the above embodiments, only the improvement of sound insulation properties was explained, but materials effective for electromagnetic shielding such as aluminum may be mixed into the electromagnetic shield, and glass fiber etc. may be added to improve the strength of the fusion layer and porous layer. , it may be mixed into resin particles and molded.

The porous structure (61) can change the degree of change in porosity depending on the thickness of the porous layer (63), etc., and can control the frequency of sound absorption characteristics, thereby improving sound absorption. By layering the fusion layer (64), the sound insulation properties are improved. Further, if necessary, a skin layer (65) with a thickness of 100 microns or less is provided on the anti-fusion layer side of the porous layer (63).

(67) is an engaging claw integrally formed on both vertical sides (60a) of the top plate (60), and (68) is an engaging hole provided on both vertical sides (52a) of the chassis (52).

In the above embodiment configuration, the mechanical part main body (53) is fixed to the chassis (52) with screws, and the fan motor (55) is fixed to a part of the sheet metal structure of the mechanical part main body (53) with screws. This and the screwing of the rear plate (54) to the chassis and the fitting and fixing of the design panel (56) are the same as in the conventional device shown in FIG. 19.

Figure 2 is a schematic diagram showing the structure of how the top plate (60) is attached to the chassis (52), and as shown in Figure (A), the top plate (60) is placed over the mechanical body (53) from above. By doing so, the chassis (52) as shown in the same figure (B)
The elastic engagement claw (67) fits into the retention hole (68) of the top plate (68) while being deformed, and the top plate (
60) can be assembled and fixed to the chassis (52). Since the top plate (60) is made of a porous structure with good sound absorption, the fan motor (55) and the mechanical part main body (5
3) Reduce noise from leaking to the outside of the device.

In the above embodiment, only the top plate (60) is formed of a porous structure, but the rear plate (54) and the design panel (56) are also formed of a porous structure, and the entire device main body is made of a porous structure. By surrounding it with a porous structure, the sound insulation effect can be further enhanced.

[Effects of the Invention] As described above, according to the present invention, the main body of the mechanical part that generates noise is covered with a porous structure having good sound absorption, so that noise from the noise source is not transmitted to the outside of the device. It has less leakage, improves the soundproofing effect, and prevents noise pollution in the area around which the device is installed.This porous structure also has an integrally molded engagement claw that allows it to be assembled to the chassis without the need for screws. Therefore, there is an effect that a printer device with good assemblability can be obtained.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing a printer device according to an embodiment of the present invention, FIG. 2 is a schematic diagram illustrating the assembly of the top plate of the device, and FIG. 3 is a multilayer material (porous material) used in the present invention. FIG. 4 is a cross-sectional view of a mold configuration for manufacturing a porous structure, and FIG. 5 is a first embodiment of a porous structure used in the present invention. Figure 6 is a curve diagram showing the porosity versus body stiffness; Figure 6 is a characteristic curve diagram of the normal incidence sound absorption coefficient of the porous structure whose porosity curve is shown in Figure 5; A characteristic diagram showing the variation in normal incidence sound absorption coefficient characteristics when changing the shape of the granular material to be formed. Figure 8 is a characteristic diagram showing the relationship between the diameter of the granular material and sound absorption coefficient. Figure 9 is a layered porous material. FIG. 10 is a curve diagram showing the porosity with respect to the thickness of the porous structure of the third embodiment used in the present invention. FIGS. thing and first
Figure 13 is a curve diagram comparing the characteristics of normal incidence sound absorption coefficient with a porous structure whose porosity curve is shown, and Figure 13 shows the porosity of the porous structure having a skin layer used in the present invention. 14 is a characteristic curve diagram of normal incidence sound absorption coefficient of a porous structure having a skin layer whose porosity curve is shown in FIG. 13, and FIG. 15 is a characteristic curve diagram of an arbitrary layered porous structure used in the present invention. 16 is a cross-sectional view of the structure of a mold for manufacturing a porous structure containing iron particles, FIG. 17 is an explanatory diagram of a characteristic measuring device for measuring sound insulation characteristics, and FIG. 18 is a diagram of the present invention. 19 is an exploded perspective view of a conventional printer device, and FIG. 20 is a schematic diagram illustrating the assembly of the top plate of the device. In the figure, (53) is the main body of the machine, (55) is the fan motor (noise generation source), (61) is the porous structure, (6
3) is a porous layer, and (64) is a fusion layer. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A porous structure that has a porous layer whose specific gravity is continuously changed in the thickness direction or the surface direction of the layer, and an impermeable fused layer that is fused and integrated to one side of this porous layer. 1. A printer device, characterized in that the printer body is covered with the porous layer on the inside and the fused layer on the outside.